Coaxial cable transmission lines can be used to route radio frequency (rf) signals throughout a home. The characteristics of a coaxial cable determine what maximum frequency the cable will support for high quality (e.g., high signal-to-noise ratio) transmission of analog or digital signals. Older cable existing in many homes may support high quality transmission of signals up to around 900 MHz. Other types of cable (e.g., cable used for satellite television signals) may support higher frequencies up to around 1700 MHz. The frequency limit also determines the maximum data rate limits for digital signals (e.g., digital video or internet protocol (IP) data packets).
A cable signal typically enters a home over a single source port and from there is distributed throughout the home. A distribution network of coaxial cable is typically formed by connecting cables to splitters that passively couple an incoming signal to two or more output ports. This network typically has a tree topology in which information flows downstream from the source (at the “root” of the tree) to each terminating device such as a television, set top box, or cable modem (the “leaves” of the tree). In some cases (e.g., for a cable modem or interactive television service) information also flows upstream from a terminating device to the source port.